From 0f714ca2b3f32fe2b4f3a7222c8066b77ea25a51 Mon Sep 17 00:00:00 2001 From: Srikar Dronamraju Date: Wed, 4 Sep 2019 15:17:38 +0530 Subject: perf stat: Fix a segmentation fault when using repeat forever [ Upstream commit 443f2d5ba13d65ccfd879460f77941875159d154 ] Observe a segmentation fault when 'perf stat' is asked to repeat forever with the interval option. Without fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.000211692 3,13,89,82,34,157 cycles 10.000380119 1,53,98,52,22,294 cycles 10.040467280 17,16,79,265 cycles Segmentation fault This problem was only observed when we use forever option aka -r 0 and works with limited repeats. Calling print_counter with ts being set to NULL, is not a correct option when interval is set. Hence avoid print_counter(NULL,..) if interval is set. With fix: # perf stat -r 0 -I 5000 -e cycles -a sleep 10 # time counts unit events 5.019866622 3,15,14,43,08,697 cycles 10.039865756 3,15,16,31,95,261 cycles 10.059950628 1,26,05,47,158 cycles 5.009902655 3,14,52,62,33,932 cycles 10.019880228 3,14,52,22,89,154 cycles 10.030543876 66,90,18,333 cycles 5.009848281 3,14,51,98,25,437 cycles 10.029854402 3,15,14,93,04,918 cycles 5.009834177 3,14,51,95,92,316 cycles Committer notes: Did the 'git bisect' to find the cset introducing the problem to add the Fixes tag below, and at that time the problem reproduced as: (gdb) run stat -r0 -I500 sleep 1 Program received signal SIGSEGV, Segmentation fault. print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 866 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep); (gdb) bt #0 print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866 #1 0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938 #2 0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=) at builtin-stat.c:1411 #3 0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 , argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370 #4 0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429 #5 0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473 #6 0x000000000045cac9 in main (argc=, argv=) at perf.c:588 (gdb) Mostly the same as just before this patch: Program received signal SIGSEGV, Segmentation fault. 0x00000000005874a7 in print_interval (config=0xa1f2a0 , evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 964 sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep); (gdb) bt #0 0x00000000005874a7 in print_interval (config=0xa1f2a0 , evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964 #1 0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 , _target=0xa1f0c0 , ts=0x0, argc=2, argv=0x7fffffffd670) at util/stat-display.c:1172 #2 0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656 #3 0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960 #4 0x00000000004dd2e0 in run_builtin (p=0xa30e00 , argc=5, argv=0x7fffffffd670) at perf.c:310 #5 0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362 #6 0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406 #7 0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531 (gdb) Fixes: d4f63a4741a8 ("perf stat: Introduce print_counters function") Signed-off-by: Srikar Dronamraju Acked-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Tested-by: Ravi Bangoria Cc: Namhyung Kim Cc: Naveen N. Rao Cc: stable@vger.kernel.org # v4.2+ Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/builtin-stat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tools/perf') diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index e77880b5094d..65a6922db722 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -1416,7 +1416,7 @@ int cmd_stat(int argc, const char **argv, const char *prefix __maybe_unused) run_idx + 1); status = run_perf_stat(argc, argv); - if (forever && status != -1) { + if (forever && status != -1 && !interval) { print_counters(NULL, argc, argv); perf_stat__reset_stats(); } -- cgit v1.2.3 From 6d4d8a07ba567b8396c32bfdf2e38869b44c5d8a Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Thu, 26 Sep 2019 15:00:18 -0700 Subject: perf llvm: Don't access out-of-scope array commit 7d4c85b7035eb2f9ab217ce649dcd1bfaf0cacd3 upstream. The 'test_dir' variable is assigned to the 'release' array which is out-of-scope 3 lines later. Extend the scope of the 'release' array so that an out-of-scope array isn't accessed. Bug detected by clang's address sanitizer. Fixes: 07bc5c699a3d ("perf tools: Make fetch_kernel_version() publicly available") Cc: stable@vger.kernel.org # v4.4+ Signed-off-by: Ian Rogers Cc: Alexander Shishkin Cc: Andi Kleen Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Wang Nan Link: http://lore.kernel.org/lkml/20190926220018.25402-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman --- tools/perf/util/llvm-utils.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'tools/perf') diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 62f6d7dc2dda..9d02aa93ef90 100644 --- a/tools/perf/util/llvm-utils.c +++ b/tools/perf/util/llvm-utils.c @@ -214,14 +214,14 @@ static int detect_kbuild_dir(char **kbuild_dir) const char *prefix_dir = ""; const char *suffix_dir = ""; + /* _UTSNAME_LENGTH is 65 */ + char release[128]; + char *autoconf_path; int err; if (!test_dir) { - /* _UTSNAME_LENGTH is 65 */ - char release[128]; - err = fetch_kernel_version(NULL, release, sizeof(release)); if (err) -- cgit v1.2.3